Sulfamoyl urea derivatives

ABSTRACT

The invention relates to herbicidally active sulfamoyl urea derivatives, including herbicidal formulations and uses thereof to control the growth of noxious plants, i.e., weeds.

FIELD OF THE INVENTION

This invention relates to herbicidally active sulfamoyl urea derivatives, including herbicidal formulations uses thereof to control the growth of noxious plants, i.e., weeds.

DESCRIPTION OF THE INVENTION

This invention concerns sulfamoyl urea derivatives represented by the Formula I: ##STR1## wherein:

Y is oxygen or sulfur;

Z is N or CH;

R¹ and R² are the same or different and represent halogen, C₁ to C₄ alkyl or alkoxy;

R³ and R⁴ are the same or different and represent hydrogen, C₁ to C₄ alkyl, alkoxyalkyl,

R⁵ is hydrogen, benzoyl, or up to C₆ alkyl, haloalkyl, acyl, haloacyl, alkoxyacyl, carbamyl, N-alkylcarbamyl, N,N-dialkylcarbamyl, carboxyalkyl or carboalkoxyalkyl;

R⁶ is C₁ to C₆ alkyl, haloalkyl, or alkoxyalkyl; and

R⁷ is hydrogen, halogen or C₁ to C₄ alkyl or haloalkyl.

It is, of course, to be understood that agronomically suitable cationic salts as well as stereo and optical isomers of the Formula I compounds are within the scope of this invention.

The Formula I compounds may conveniently by prepared in a two-step reaction, involving reacting in the first step a suitably substituted amino pyrimidine or amino triazine of the Formula II: ##STR2## wherein R¹, R², R³ and Z are as previously defined, with a halosulfonyl isocyanate of the formula OCN-SO₂ -Hal, wherein Hal is halogen, e.g., chlorine, fluorine or bromine to form the corresponding halosulfonyl urea of the Formula III: ##STR3##

In the second step, the Formula III compound is reacted with at least a stoichiometric amount of a suitably substituted amine of the Formula IV: ##STR4## wherein R⁴, R⁵, R⁶ and R⁷ are as previously defined, to form a Formula I compound of the invention.

The invention is further illustrated by the following Examples which describe preparation of certain compounds of this invention.

The following Examples are illustrative of the preparation of certain preferred compounds of this invention.

EXAMPLE I Preparation of: 1-[2-(1-hydroxyethyl)phenylsulfamoyl]-3-(4-methyl-6-methoxy-1,3,5-triazin-2-yl)urea

To 75 milliliters of methylene chloride maintained at 0°-5° C. via an ice bath were added 1.4 grams of 4-methyl-6-methoxy-2-amino-1,3,5-triazine and 1.55 grams of chlorosulfonyl isocyanate. After stirring for 3 hours at ice bath temperature a methylene chloride solution containing 1.0 gram of triethylamine and 1.37 grams of 2-(1-hydroxyethyl)aniline was added dropwise. The reaction mixture was removed from the ice bath, allowed to stir an additional one-half hour and then poured into 100 milliliters of 2 percent aqueous hydrochloric acid solution. After phase separation, the organic layer was washed in water and concentrated on a rotary evaporator affording a dark oil. Addition of diethyl ether to the dark oil resulted in the formation of a precipitate which was filtered-off. The filtrate was evaporated and the residue was taken-up in chloroform and again evaporated affording a powdery solid. Vacuum drying afforded 1.7 grams of light tan solid confirmed by NMR analysis as the desired product.

EXAMPLE II Preparation: 1-[2-(1-hydroxyethyl)phenylsulfamoyl]-3-(4-methyl-6-methoxy-1,3,5-triazin-2-yl)urea, acetate ester

To a chloroform solution of 2 equivalents of the sulfamoyl urea prepared as described in Example I were added, with stirring, 2 equivalents of triethylamine and 2 equivalents of acetic anhydride. The reaction mixture was allowed to stand quiescent for 24 hours and was then poured into dilute aqueous hydrochloric acid and phase separated. The organic layer was washed with water and extracted with saturated aqueous sodium carbonate. The basic extract was filtered and the filtrate acidified with cold dilute aqueous hydrochloric acid resulting in formation of a white precipitate. After suction drying, the precipitate was dried in a vacuum oven affording 1.0 gram of material confirmed by NMR analysis as the desired product.

EXAMPLE III Preparation of: 1-[2-(1-methoxyethyl)phenylsulfamoyl]-3-(4-methyl-6-methoxy-1,3,5-triazin-2-yl)urea

To 75 milliliters of methylene chloride maintained at 0°-5° C. via an ice bath were added 1.4 grams of 4-methyl-6-methoxy-2-amino-1,3,5-triazine and 1.55 grams of chlorosulfonyl isocyanate. After stirring for 3 hours at ice bath temperature a methylene chloride solution containing 1.0 gram of triethylamine and 1.4 grams of 2-(1-methoxyethyl)aniline was added dropwise. The reaction mixture was removed from the ice bath, allowed to stir an additional one-half hour and then extracted with aqueous sodium carbonate solution. Acidification with cold, dilute aqueous hydrochloric acid solution afforded a white precipitate which was suction filtered and vacuum dried affording 2.2 grams of material confirmed by NMR analysis as the desired product.

Although the invention has been illustrated by the foregoing Examples with regard to the preparation of certain compounds within the scope of Formula I, it is to be understood that other compounds within the scope of Formula I may readily be prepared by those skilled in the art simply by varying the choice of starting materials and using the same or similar techniques.

Weed control in accordance with this invention is effected by applying to the soil prior to emergence of weeds therefrom or to the plant surfaces subsequent to emergence from the soil, a herbicidally effective amount of a compound of this invention. It is, of course, to be understood that the term "a compound of this invention" also includes mixtures of such compounds or a formulation containing a compound or mixture of compounds of this invention.

The term "herbicidally effective amount" is that amount of a compound of this invention required to so injure or damage weeds such that the weeds are incapable of recovering following application while not causing substantial injury to any valuable crop amongst which the weeds might be growing. The quantity of a compound of this invention applied in order to exhibit a satisfactory herbicidal effect may vary over a wide range and depends on a variety of factors, such as, for example, hardiness of a particular weed species, extent of weed infestation, climatic conditions, soil conditions, method of application, and the like. Typically, as little as one or less pound per acre of a compound of this invention would be expected to provide satisfactory weed control, although in some instances application rates in excess of one pound per acre, e.g., up to 5 or more pounds per acre might be required. Of course, the efficacy of a particular compound against a particular weed species may readily be determined by routine laboratory or field testing in a manner well known to the art. It is expected that satisfactory weed control can be had at a rate of application in the range of 0.1 to 2.0 pounds per acre.

Of course, a compound of this invention can be formulated according to routine methods with any of several known and commonly used herbicidal diluents, adjuvants and carriers. The formulations can contain liquid carriers and adjuvants and carriers. The formulations can contain liquid carriers and adjuvants such as organic solvents, as well as emulsifiers, stabilizers, dispersants, suspending agents, spreaders, penetrants, wetting agents and the like. Typical carriers utilized in dry formulations include clay, talc, diatomaceous earth, silica and the like. Preferred formulations are those in the form of wettable powders, flowables, dispersible granulates or aqueous emulsifiable concentrates which can be diluted with water at the site of application. Also, dry formulations such as granules, dusts, and the like, may be used.

When desired, a compound of this invention can be applied in combination with other herbicidal agents in an effort to achieve even broader vegetative control. Typical herbicides which can be conveniently combined with Formula I compound include atrazine, hexazinone, metribuzin, ametryn, cyanazine, cyprazine, prometon, prometryn, propazine, simazine, terbutryn, propham, alachlor, acifluorfen, bentazon, metolachlor and N,N-dialkyl thiocarbamates such as EPTC, butylate or vernolate. These, as well as other herbicides described, for example, in the Herbicide Handbook of the Weed Science Society of America, may be used in combination with a compound or compounds of the invention. Typically such formulations will contain from about 5 to about 95 percent by weight of a compound of this invention.

The herbicidal formulations contemplated herein can be applied by any of several method known to the art. Generally, the formulation will be surfaced applied as an aqueous spray. Such application can be carried out by conventional ground equipment, or if desired, the sprays can be aerially applied. Soil incorporation of such surface applied herbicides is accomplished by natural leaching, and is of course facilitated by natural rainfall and melting snow. If desired, however, the herbicides can be incorporated into the soil by conventional tillage means.

Compounds of this invention are believed effective for preemergence or postemergence control of a wide variety of broadleaf and grassy weeds. Typical of the various species of vegetative growth that may be controlled, combated, or eliminated are, for example, annuals such as pigweed, lambsquarters, foxtail, crabgrass, wild mustard, field pennycress, ryegrass, goose grass, chickweed, wild oats, velvetleaf, purslane, barnyardgrass, smartweed, knotweed, cocklebur, kochia, medic, ragweed, hemp nettle, spurrey, pondweed, carpetweed, morningglory, ducksalad, cheatgrass, fall panicum, jimsonweed, witchgrass, watergrass, wild turnip, and similar annual grasses and weeds. Biennials that may be controlled include wild barley, campion, burdock, bull thistle, roundleaved mallow, purple star thistle, and the like. Also controlled by the compounds of this invention are perennials such as quackgrass, Johnsongrass, Canada thistle, curly dock, field chickweed, dandelion, Russian knapweed aster, horsetail, ironweed, sesbania, cattail, wintercress, horsenettle, nutsedge, milkweed, sicklepod, and the like.

The compounds prepared as described in the Examples were individually tested for herbicidal efficacy against a variety of broadleaf and grassy weed species, under controlled laboratory conditions of light, humidity and temperature. A solvent solution of each compound was applied, both preemergence and postemergence, to test flats containing the various weed species, and herbicidal efficacy was determined by periodic visual inspection, after application of the compounds vis a vis an untreated control. Herbicidal efficacy was determined on a Numerical Injury Rating (NIR) scale of from 0 (no injury) to 10 (all plants dead). A NIR rating of 7-9 indicates severe injury; a NIR rating of 4-6 indicates moderate injury, i.e., plant growth is reduced to the extent that normal growth would be expected only under ideal conditions; and a NIR rating of 1-3 indicates slight injury.

The following table gives the average preemergence and postemergence NIR determined for each of the compounds prepared as described in Examples I through III on the broadleaf (BL) and grassy (GR) weed species to which the compounds were applied. Each compound was applied at a rate of 2.0 pounds per acre and the NIR was determined three weeks subsequent to application.

    ______________________________________                                                  I           II    III                                                 ______________________________________                                         Pre-BL     9.0           7.5   9.0                                             Pre-GR     9.4           8.2   8.7                                             Post-BL    4.5           4.7   5.8                                             Post-GR    4.2           5.5   4.8                                             ______________________________________                                    

The broadleaf weeds used in the screening tests were coffeeweed, jimsonweed, tall morningglory, wild mustard, teaweed and velvetleaf. The grassy weeds used in the screening tests were barnyardgrass, large crabgrass, Johnsongrass, wild oats, sicklepod, lambquarters and yellow foxtail. In addition to the above observed herbicidal activities the compounds were found very effective, especially when applied preemergence, in controlling yellow nutsedge, a weed variety that is very difficult to control.

Although the invention has been described in considerable detail by the foregoing, it is to be understood that many variations may be made therein by those skilled in the art without departing from the spirit and scope thereof as defined by the appended claims. 

I claim:
 1. A compound represented by the formula: ##STR5## wherein: Y is oxygen or sulfur; Z is N; R¹ and R² are the same or different and represent halogen, C₁ to C₄ alkyl or alkoxy; R³ and R⁴ are the same or different and represent hydrogen, C₁ to C₄ alkyl, alkoxyalkyl, haloalkyl, or up to C₃ alkenyl or alkynyl; R⁵ is hydrogen, benzoyl or lower alkanoyl R⁶ is C₁ to C₆ alkyl, haloalkyl, or alkoxyalkyl; and R⁷ is hydrogen, halogen or C₁ to C₄ alkyl or haloalkyl.
 2. A compound of claim 1 selected from: 1-[2-(1-hydroxyethyl)phenylsulfamoyl]-3-(4-methyl-6-methoxy-1,3,5-triazin-2-yl)urea; or 1-[2-(1-hydroxyethyl)phenylsulfamoyl]-3-(4-methyl-6-methoxy-1,3,5-triazin-2-yl)urea, acetate ester.
 3. A herbicidal formulation containing an agronomically acceptable carrier and a compound or mixture of compounds defined in claim
 1. 4. In a method of controlling weeds wherein a herbicidally effective amount of herbicide is applied to a growth medium prior to emergence of weeds therefrom or to the weeds subsequent to their emergence from the growth medium, the improvement residing in using as the herbicide a compound or mixture of compounds defined in claim
 1. 